Arc-welding machine



Sept. 29, 1936. R K, HCPKlNs 2,055,533

ARC WELDING MACHINE Filed May 11, 1932 "F11. 4 l7 l0 5 3 2 (a: I Q

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YZ, BY D 7 ATTORNEY Patented se eza, 1936 UNITED STATES PATENT OFFICE RobertK. Hopkins, New York, N. Y., asignor to The M. W. Kellogg 00., New York, N. Y., a corporation of Delaware Application May 11, 1932, Serial No. 610,553

6 Claims. (Cl. 219-8) This invention relates in general to arc welding and in particular to a method and apparatus for carrying on as a continuous operation arcwelding in which welding rods, r electrodes covered with ceramic or other non=conducting material, are used.

.Machines capable of carrying on arc-welding as a continuous operation while using bare welding electrodes, either in the rodor coil form,

are known tothe art. The successful operation of these machines depends on the fact thatevery portion of the surface of the electrode is capable of acting as the point of application of the current. Since the covering material of the covered welding electrodes is a non-conductor of electric h current, the machines mentioned would be ren- The machines include actuating mechanisms and control means therefor for moving as a unit the electrode feeding element and the electrode fixed thereto, toward the crater of the weld at the proper rateto maintain a constant length are, and for oscillating the'electrode feeding element and the electrode across the crater of the weld. The current is passed to the electrode through the bare end thereof. When an electrode is consumed, it is necessary to break the arc and to return the electrode feeding element to a position sufliciently removed from the crater of the weld to allow the fixing of a new electrode thereto. Since the electrode feeding element moves at substantially thesame maximum rate in both directions, about one-half of the operating time of the machine is'taken up in returning the electrode feeding element. The interval between the breaking of the arc and the starting of a new electrode is sufliciently long to cause a substantial cooling of the weld. This, added to the fact that the metal deposited when a new are is started is generally porous, necessarily causes inherently weak spots along the weld.

The length into which the electrodes are cut is, in the main, determined by their diameter and by the current to be passed through them. Since the point of application of the current to the electrode is fixed, these electrodes heat excessively and only a comparatively short length tion of the machines at present known, the electrodes must be made of a length somewhat longer than the length which can actually be used with a consequent substantial wastage of valuable electrode material.

This invention has for an object a method and apparatus by which it is possible to carry on arc-welding with covered welding electrodes as 'a continuous welding operation.

The invention has for a further object the provision of apparatus for automatically leading the welding current to a plurality of consecutive exposed areas or pairs of areas of, the metallic core of a covered electrode.

The invention has for a further object apparatus which is adapted to feed to the are a covered electrode of indefinite length having spaced contact areas, and which includesmeans movable with the electrode adapted to automatically connect consecutive contact areas of the electrode to a welding current supply as each of said areas enters a predetermined portion of their path to the arc and adapted to automatically disconnect each of said areas from the welding current supply assaid areas leave the of their path to the arc.

The particular nature of the invention, as well as other objects and advantages thereof, will appear most clearly by reference to the accompanying drawing, wherein Figure 1 is a front elevation of an arc-welding machine embodying a preferred form of the invention,

re 2 is a front elevation of a guide member, V I

Figure 3 is a sectional plan view taken on line 33 of ure Figure 4 is a partsectional front view-of a section of the welding electrode, and

Figure 5 is a view similar to Figure 4, but with the welding electrode rotated through degrees and showing a different form. of connecting means. v

Referring to the drawing:

The welding current generator, the control means therefor as well as the welding electrode oscillating motor, etc.', which per se form no part of this invention, will for the purpose of this description be considered as located in rear of the panel I, with the welding electrode oscillating motor mounted to oscillate panel I. A welding electrode feeding motor 2, the control means of which (not shown) is located at the rear of panel I, is mounted on panel I to oscillate therewith. A grooved wheel 3 is keyed to predetermined portion ficient pressure'to prevent slippage.

the shaft of motor 2 and engages a portion of the bottom section of the welding electrode 4. The diametrically opposite portion of welding electrode 4 is engaged by a grooved wheel 5 which is mounted in a pivoted bracket 6. A spring i has one end anchored in a loop at the bottom of bracket 6, its other end being anchored in a loop on a bracket 8,,which is bolted or otherwise fastened topanel I. Spring l constantly urges wheel 5 into contact with welding electrode 4 and causes it to bear against wheel 3 with suf-- The contactportions of wheels 3 and 5 are made of fibre or some other material to prevent damage to the coating as the welding electrode 3 passes between them.

The member 9 supports the pivot of-bracket 8 and is fastened to an L-shaped guide member M which is in turn fastened by means of brackets H to panel i to oscillate therewith. The upper portion of guide member ID has fastened thereto Lspaced guide brackets l2 through which pass the sections of the welding electrodes 3 on their way to'wheels 3 and 5. The lower portion of guide member I0 is provided with a. guide hole through which passes-the welding electrode as it approaches the arc.

Thewelding electrode 4 is made up of an indefinite number of sections, that is to say, as one section is consumed, another is added'to the remaining section, or sections, and this procedure continued indefinitely. Each section, as shownin Figures 3-5, comprises a metallic core 7 63 about which is formed acovering i l of ceramic or other non-conducting:material. end of each section is provided with the-male member I5 and the other end with the female memberit of a joint forming means). The spe-.

cific form-of joint forming means is not very important} It must, however, be such that the sections may be easily and quickly joined and th'e joint must be sufliciently strong to support the weight of the welding electrode 4 below the wheels 3 and 5, also it must give a sufilciently intion and the beginning of the next. Figure 4 a shows a section provided with the members of a threaded joint and Figure 5, a section providedwith the members of a dove-tail joint.

To provide for the passage of the welding current from the current supply to the metallic core 13 of the welding electrode 3, portions of the covering i l, equally spaced apart along the length of the electrode l, are ground out or otherwise removed to expose or substantially expose small areas of the metallic core l3. The voids ll in the electrode covering i l, thus produced, approximate a'frustum of a cone in shape and as shown in Figures 3-5, expose but a small portion of the electrode core I3 while they allow ready access for contact therewith. The shape of voids ll may be varied but to produce the result intended it is essential that but a small area of the surface of metallic core i3 be exposed and a minimum amount of the circumfermember. 118.

One

be covered with metal and thus seriously weaken the weld;

In the preferred form of weldingelectrode 4,

voids I! are provided at diametrically opposite portions thereof, at points equally-spaced apart along the length thereof. This construction is very satisfactory but it is not necessary. that voids I! be so arranged as theymightbe made end of each of short shafts 20 which carry wheels The other end of each of short shafts 20 is'supported in members 22 which extend from Wheels 20 support endless metal belts'23. The middle wheel 2| is used to prevent substantial sag in belts 23: One side of the welding current is conducted from the generator, not shown, through cable 24 to a connector 25 through cables 26 and 21 to brush supports 28 and 29 which are supported from member i8. Brush supports 28 and 29 carry brushes 3!! and M which are adapted to bear on belts 23. Brush supports 28 and 29 are of the usual construction and may include spring means for constantly;

urging brushes 30 and iii into contact-with belts and is driven by an endless chain38 which passes over a sprocket wheel 39 keyed to the shaft of motor 2. Sprockets 3i and 39 are of the same diameter. Pulleys 33 and 34 have as their diameter the effective diameter of wheel 3; i. e., the.

diameter of wheel 3 which is in contact with the welding electrode 4. By this-arrangement belt 32 moves at the identical speed as welding electrode t and is subject to the identical control.

Equally spaced apart along the length of belt 32 are fastened, by rivets or other similar means,

pairs of springcontact members 33, which are adapted, as shown in Figure 3, to lead the weld-v ingcurrent from belts 23 to the metallic core E3 of welding electrode 4. The shape of the individ-" leys 33 and 34 so that the centers of top wheels-2l are below the center of pulley 33 and the centers of bottom wheels 2i are above the center of pulley 33.

When the arc-welding machine is initially ad- 8,056,533 moves toward the arc-Irom the position shown in Figure 1, the top one of the pairs of contact members 40 in contact with belts 23 will move toward the position ofthe second one of the pairs of contact members 40. At the same'time the top one of the pairs of members, on the side of belt 32 removedfrom electrode 4, will move toward the position of the top one of the pairs of contact members 40 in contact with belts 23. In going to the latter position, the members 40 of the pairs,'being distended, will pass over electrode 4 and move toward the next one of voids l1. When this pair of contact members 40 reaches the dotted position 40a members 40 will begin to contact with belts and be brought towards each'other until at the full line position, immediately below 4Da, they will contact with theexposed areas of core l3 at void l1 and lead the welding current thereto. The parts are so proportioned and arranged that contact members 40 do not contactwith electrode 4 until they reach a position at or below the centers of the top pair of wheels 2| so that there is substantially no relative movement between members 40 and electrode 4 after they are in contact with each other and wear of members 40 is avoided.

Contact members 40 in leaving electrode 4 at the bottom of guide member it pass from a dotted position 40b at which they are just above the centers of the bottom pair of wheels 2| to the solid line position immediately below. In going to the latter position, the members 40 separate by reason of the increasing space between belts 23 and when they reach the latter position are spaced apart suificiently to be out of contact with electrode 4. Because of this arrangement, there is no relative movement between members 40 and electrode 4 when they are in contact with each other.

The members 40 in going from the top to the bottom position carry belts 23along with them. This eliminates wear on members 48 and prevents sparking. It is to be noted that a plu rality of members 40 are in contact at all times with the exposed portions of core l3 and that the welding current passes to the core l3 through a plurality of points. Because of this, there is no sparking, or at worst, only a negligible amount of sparking, when members 40 make or break contact with the exposed portions of core 53.

While preferred forms of the apparatus have been shown and described and a preferred meth od has been disclosed, it will be understood that the invention may be embodied in other forms, that various changes may be made in the'struc- Mira]. details or the apparatus. and that the methcd may be modified without departing from the principle or the invention as defined in the an pended claims.

I claim:

i. In an arc-welding machine adaptm to use a welding electrode having a conducting core and a non-conducting covering broken at spaced in= towels to expose small areas of the core, meam for feeding the electrode to the arc, welding cur rent supply means, movable endless means ex-= tending between predetermined points in the electrode path connected to said welding current supply means and means movable in an endless path a portion or which includes the portion of said electrode path between said predetermined points for connecting said areas to said endless means as said areas pass through the portion or said electrode path between said predetermined 2. In an arc-welding machine adapted to use a welding electrode having a conducting core and anon-conducting covering broken at spaced intervals to expose small areas of the core, means for feeding the electrode to the arc, welding current supply means, endless means positioned ad jacent the electrode path and connected to said welding current supply means, said endless means being movable in a path a portion of which is parallel to the path of the electrode and extends between predetermined points in the path of the electrodes and means movable in an endless path which includes the portion of said electrode path between said predetermined points for connecting said areas to said endless means as said areas pass through the portion of said electrode path between said predetermined points.

3. In an arc-welding machine of the character described in which a welding electrode is fed to an arc struck between said electrode and the work, the combination of means for feeding the electrode to the arc, welding current supply means, a support positioned adjacent the path of said electrode, a pair, of spaced endless members mounted for movement on said support, means for conducting welding current'i'rom said supply means to said endless, members and contact members movable with said electrode between two predetermined points in the path of the electrode adapted to contact with said endless members and the electrode while moving with the electrode between said predetermined points in said path.

4. In an arc-welding machine of the character described in which a welding electrode is fed to an arc struck between said electrode and the work, the combination of means for feeding the electrode to the arc, welding current supply means, a support positioned adjacent the path of said electrode, a pair of parallel spaced endless members supported on said support, each of said endless members being movable in a path having curved end portions and a straight middle portion, means connecting said endless members to said current supply means, and contact means movable between said endless members, said oon= tact means being adapted to contact with the electrode and said endless members as said con= tact members move between the middle portion of the paths of said endless members.

In an arc-welding machine adapted to use a weicling electrode having a conducting" core and a non=conducting cover g broken tervels to expose small areas of the core, means for feeding the electrnde to the arc, welding current supply means, a support positioned adiaeent path of said electrode, a of end less members supported on said support for movement in a path, the of each endless members including curved end por tiom and middie portions define be tween said endless members a groove end of chwging width and a portion of constant width, means connecting said and less members to said welding supply means, an endless member positional said eiectrcde on the side opposite support, spaced contact members fined to said last men tioned endless member and movable through groove to contact with said exposed areas said first mentioned endless members, and means for moving said last mentioned endless at the speed of the electrode.

6. In an arc-welding machine, the combineconducting endless belts supported for movement in fixed paths on'said support, means connecting said belts to said current supply means, a third endless belt supported for movement in a fixedv path adjacent said electrode on the side oppo site said support, ,spaced contact members fixed to said third endless belt adapted to'contactwith said pair of endless belts and said electrode and means for moving said third endless belt at the speed of the electrode. ROBERT K. HOPIQNS. 

